You can now create YAML-formatted templates to describe your AWS resources and properties in AWS CloudFormation. Now, you have the option to use either YAML-formatted templates or JSON-formatted templates to model and describe your AWS infrastructure. YAML-formatted CloudFormation templates follow the same anatomy as existing JSON-formatted templates and support all the same features.

You can now also create cross stack references that let you share outputs from one stack with another stack. This lets you share things such as IAM roles, VPC information, and security groups. Previously, you needed to use CloudFormation custom resources to accomplish this. Now, you can simply export values from one stack and import them to another stack using the new ImportValue intrinsic function. Cross stack references are useful for customers who separate their AWS infrastructure into logical components grouped by stack (e.g. a network stack, an application stack, etc.) and who need a way to loosely couple stacks together as an alternative to Nested Stacks.

Additionally, CloudFormation has introduced a new intrinsic function, Fn::Sub. This function substitutes variables in an input string with values that you specify.

Learn more about these new features by reading the AWS blog. You can also view the documentation topic for YAML-formatted templates here. Visit here for an introduction to CloudFormation template basics. CloudFormation Designer does not currently support YAML templates.